Acellular urinary casts Granular casts 2017-06-27T11:06:58Z It has been demonstrated that in patients with proteinuria, fine granules contain ultrafiltered proteins which have been reabsorbed by tubular cells, whilst in non-proteinuric patients coarse granules probably derive from the degeneration of cellular elements, such as leukocytes and renal epithelial cells present in the tubular lumen during cast formation. A type of acelluar casts that have a surface composed of granules, which can vary in size. The granules can be rather heterogeneous, ranging from fine (finely granular cast) up to coarse (coarsely granular cast), dark, clear, and pigmented.